This invention is directed to the field of archery, and more specifically to compound bows of the type employing cams and control cables to achieve a programmed draw weight, and the latter being variable with draw length. The invention is more particularly concerned with improvements to such compound bows which make the bows more compact and streamlined, and which permit the archer to select the bow's draw characteristic, and which increases the bow's shooting performance.
A bow of this general type is described in my earlier U.S. Pat. No. 5,388,564. That patent is incorporated herein by reference. Archery bows with programming means incorporated into them to regulate draw weight are also described in U.S. Pat. Nos. 3,854,417; 3,923,035; 3,486,495; and 4,287,867. These bows have means to regulate their draw weight so that a maximum pull weight is attained at an intermediate draw position, and with the draw weight dropping to some fraction of full draw weight at the full draw position. It is also an objective of such bows to transfer as much of the energy stored in the bow to the arrow, so that the arrow will fly faster and farther for a given draw weight. These have been difficult to achieve.
Current state of the art hunting bows, for example the Oneida Labs X80 models sold since about 1994, have a hinge connecting the rigid outer limb to the end of the power limb, so that the proximal end of the outer limb projects past the end of the power limb, and has to lie on top of the power limb when the bow is in the released condition. When the bow is drawn, the proximal end of the outer limb swings up above the power limb. This creates one more part of the bow that can catch on brush or clothing, and also detracts from any attempt to give the bow a streamlined appearance.
Also in the prior art bow, the cable that runs from the cam (and synchronizing wheel) up to the outer limb is fixed to a point on the outer limb. When the bow is drawn, the cable bends at the point where it is affixed, and the cable fatigues and eventually will fail at that point. When this occurs, the bow has to be returned for refitting with a new cable. If this happens in the field, it can spoil a hunting trip.